When I graduated college almost ten years ago and was moving out of the dorms on campus, my father picked me up in his graduation gift to me, a “new” (to me) 1988 Toyota Celica. From this point on, it was my responsibility to care for and maintain the car, but I didn’t really know what that entails.

I found out several months later while I was driving on Interstate 95 in Delaware. Without much warning—or without any warning that I recognized at the time—I heard a loud bang! from under the hood and the car no longer accelerated as I depressed the pedal. I pulled over to the side of the road to keep my broken-down Celica out of the way of traffic and walked to the nearest motorist assistance phone on the highway. This was a few years before I would own a cellular phone, so I had no choice but to risk myself with a leisurely walk alongside the breakdown lane of a major highway.

Well, apparently, cars require not only an oil change once in a while, but the occasional addition of oil to keep the engine lubricated. This knowledge is familiar to most people, I think, but perhaps not to a kid who is taking care of his own car for the first time. From this point on, I don’t know how many people reminded me that you should Check Your Oil Whenever You Get Gasoline and Have Your Oil Changed After Driving 3,000 Miles.

So that’s what I did. I discovered a few things after having the motor replaced in the Celica. First, the rebuilt engine that was installed burned through oil very quickly. I had to add more oil every few weeks just to keep the dip stick reading at “full” and the frequency of oil changes was about once a month.

I had the Celica for at most two years. When I needed a more reliable car in late 1999 or early 2000, I traded it in for a lightly-used 1997 Honda Civic and the accompanying monthly car payment. With this car, I did not need to add new oil so frequently. I also noticed that it took a longer time before the oil blackened so I figured this car might be able to last more than 3,000 miles without changing the oil. The Civic operated fine when waiting 5,000 to 8,000 miles between oil changes.

A number of circumstances led to the need for a car disappearing, and I gave the Civic to a friend of the family for her son’s use while in high school. Eventually, I received the car back but it wasn’t as reliable as it had once been. It wasn’t long before I sold the car and purchased a new 2004 Honda Civic. This car’s oil held up even better. According to the owner’s manual, the oil in the 2004 Honda Civic should be changed every 10,000 miles or one year, whichever comes first. Even four years and almost 90,000 miles later, the oil does not seem to ever get dirty, so I find myself stretching even that to 15,000 miles while still feeling comfortable that I won’t be damaging the car. The other part of my reasoning is to save money on maintenance costs, but I don’t want to find myself penny wise, pound foolish and spending more money to fix major damage.

Maybe the 3,000 mile guideline is only appropriate for older cars, but I’ve talked to many people with newer cars who agree that this is mostly a myth perpetuated by the industry.

According to Honda Owner Link, a personalized record-keeping and maintenance website available to Honda owners, this is better advice for oil changes:

There is absolutely no benefit in changing your oil more frequently than recommended in your owner’s manual. This will only increase your cost of ownership, and create an unnecessary burden upon the environment by increasing the amount of disposed oil.

Do not exceed the recommended maintenance interval. Oil eventually deteriorates and loses its ability to protect your engine, due to heat, friction, and exposure to exhaust components. Engine oil contains special additives to enhance the oil’s performance, and these additives are also broken down or consumed with distance and time. Engine damage can occur if the proper maintenance schedule is not followed.

The 2004 Honda Civic Owner’s Manual explicitly instructs owners to have the car’s engine oil changed every 10,000 miles, and I should force myself to stay on this schedule, particularly as I approach 100,000 miles.

If you own a car, how often do you change your oil?

On Monday I began debunking retirement myths with the help of Money Magazine with the first seven of 13. Today I’m presenting the remaining 6 common errors in thinking.

Myth #8: Your house can finance retirement. I’ve said this before—your house is not a retirement plan. Real estate investments are another matter; unlike other investments, the house you live in provides your shelter and is harder to cash in. You have to live somewhere. In order to start seeing the value of your house in cash, you have to downsize. Another option, a reverse mortgage in which you slowly sell your equity back to a bank, will leave you with no asset to leave to your heirs.

Myth #9: You’re too old to start saving. This is pretty straightforward. It’s never too late to start putting away money for retirement. Of course, it will be much more difficult to amass significant savings starting within earshot of the end of your career, and some sacrifices will be necessary. That might mean downsizing your house and socking away the difference or cutting back expenses.

Myth #10: Short-term market swings don’t matter. This is the mantra of the long-term investor. The daily or monthly ups and downs are irrelevant because over the long term, the stock market provides returns higher than inflation. The truth is that as you grow closer to when you’ll need to access the cash value of your portfolio, those short-term swings can be devastating. That is why your asset allocation, the mix of investments, is important. As you approach retirement, your portfolio should include a smaller portion of stocks and a larger portion of low-risk investments like bonds.

Myth #11: Top priority is the kids’ college. If you can’t fund your own future as well as your children’s education, you have to make some choices. You could always borrow money for your kid’s education while you can’t do so for your own retirement. Now, you could change some of your expectations, such as an adequate rather than dream-fulfilling retirement home or state schools rather than Ivy League schools for your kids, but when it comes down to it, your own needs come first. At least that’s what the financial community generally believes.

Now you can hope that if you help your children pay for an excellent education, they will get excellent jobs with excellent paychecks, and will use their funds to support their parents in retirement and old age. But no matter how much you spend on an education, that’s never a sure thing.

Myth #12: Decent savings plan = early retirement. Early retirement itself is almost a myth. You’re going to have to be very aggressive with savings and investing if you intend on ending up with a portfolio that’s going to allow you to live off its own income for 30 to 40 years or more. Are you saving one third of your pay after taxes? If not, you’re not on the path to early retirement.

Myth #13: You’re bound to mess up your 401(k). 401(k)s can be easy, but with companies offering a multitude of options, and in some cases making it difficult to determine the true cost of funds, it has become much easier to make a mess. Companies have countered this by offering financial guidance for their employees enrolled in the retirement investment plans. Companies often automatically enroll new employees in 401(k) with default options, which are usually good enough if never touched, only increased, to keep a solid investment plan in gear.

Myths exist because they resonate with enough human minds to be able to convince people of their truthiness without much support.